This project, a collaborative effort by the NCI, National Academy of Sciences, National Oceanic and Atmospheric Administration, Environmental Protection Agency and others, was initiated to provide epidemiologic data relative to skin cancer and solar ultraviolet radiation. An urgent need for these data has existed since recent scientific reports have warned about the decomposition of stratospheric ozone by nitrogen oxides and chlorofluoromethanes (CFM's). Federal regulatory agencies have already recommended bans on the use of aerosol spray cans which use CFM's as propellants. Various reports from the National Academy of Sciences have suggested that there may be as much as a five to 16% depletion in stratospheric ozone sometime during the next century. Critical reviews must be made of all pertinent information dealing with estimates of increased human skin cancer due to excess amounts of UV reaching the earth's surface. As mandated by Public Law 95-95 (amendment of the Clear Air Act of 1977), the NCI is continuing its studies in this area. As more surveys are included more reliable estimates of the degree of morbidity from skin cancer will be derived. In addition, new estimates of skin cancer risks adjusted for certain host and environmental factors (including those other than UV exposure) will be ascertained (e.g., ethnicity, skin complexion, exposure to ionizing radiation, coal tar, skin conditions other than cancer, occupation). These data should enhance the progress of other programs dealing with skin cancer prevention, intervention or screening. As nonmelanoma skin cancer (i.e., basal cell and squamous cell carcinoma) information is not being routinely collected by the NCI (Surveillance, Epidemiology, and End Results), final results from this project will also complement our program's task in providing data for all malignancies.